Ditching and terracing level.



No. 700,7I7'. v Patented May 20, I902.

E. A. BOSTBOM.

DITCHING AND TEBBAGING LEVEL.

(Application filed Feb. 18, 1901.) (No Model.) 2 SheetsSheet I.

FIG. 5

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INVENTORY Tm: NORRIS FEYERS ca, PNOTO-LITHO wumnamu. n. c.

No. 700,7!7. Patented May 20, I902.

E. .A. aosmqm.

DITOHING AND TEBRACING LEVEL.

(Application filed Fab. 18, 1901.) ,(No Model.) -2 Sheets-Sheet 2.

WITNESSES I INVENTOR W ERNST A.Bos'rnom.

ATTORNEY.

THE' Nomins PETER$ co 'FHQTOLITHD wAsumzrroN. law '6.

UNITED STATES PATENT ()FFIGE.

ERNST A. BOSTROM, OF ATLANTA, GEORGIA.

DlTCHlNG AND TERRACING LEVEL.

SPECIFICATION forming part of Letters latent No. 700,717, dated May 20, 1902. Application filed February 18,1901. Serial No. 47,892. (No model.)

To all whom, it 12mg concern: of said screw, so that the circle-plate will be Be it known that I, ERNST A. BOSTROM, a always pressed downwardly to a bearing on citizen of the United States of America, and the ends of the screws 1), so that the angle a resident of Atlanta, in the county of Fulton of said circle-plate will be reliably influenced 55 and State of Georgia, have made a certain by said screws and the horizontal plane be new and usefulDitching and TerracingLeVel; obtained on its upper side and especially in and I do hereby declare the following to be l the finished seat therein for the turret D, a full, clear, and exact description of the inl which I will now proceed to describe. This Vention, such as will enable others skilled in turret D consists of an annular body finished 60 the art to which it appertains to make and on its periphery perfectly cylindrical and use the same, reference being had to the achaving its edges faced off parallel to each companying drawings, and to letters of refother.

erence marked thereon, which form a part of d and d are diametrically opposite bosses, this specification. one of which, d, is perforated radially of the 65 This invention relates tolevels, having parturret D to fit the sighting-tube E, which ticular reference to the more inexpensive passes through these bosses, the hole in the class of such devices which are useful and other boss, (1', being slotted, (elongated,) so sufficiently accurate for ditching and terracthat the said tube E may be adjusted by the ing as practiced on farms, for builders use Screws 6, so that it will lie in practically ab- 70 2a in laying foundations, 85c. solute parallelism to the aforesaid finished I The invention consists of the device hereedges of the annular turret. Given a horiinafter fully described, and shown in the aczontal plane on the upper side of the circlecornpanying drawings, in whichplate 0, it is obvious that premising parallel Figure 1 is a side elevation of the device. edges of the turret and parallelism of the tube 75 Fig. 2 is a face View of the device for obtain- E a reliable horizontal plane may be projected ing predetermined deflections from the horiby revolving the turret in its seat. Also zontal or vertical. Fig. 3 is a detail of the should the parallelism of the tube be disspring used thereon. Fig. 4: is a sectional turbed the turret may be turned over and detail of the universal joint. Fig. 5 is aplan sighted at a point in both positions, noting 8o of the revoluble turret. Fig. 6 is a section the variation, and the parallelism of the tube thereof at a right angle to the sighting-tube. to both edges be reinstated. With this pro- In the figures like reference characters are vision and an adjustable spirit-level on the uniformly employed in the designation of tnrret,snch as I will now'proceed to describe, corresponding elements of construction in all any disturbance of the adjustment of said 85 3 5 the views. tube or spirit-level may be corrected without A is the tripod-iron, to the lugs a of which especial skill. As best shown in Fig. 5, other the three legs forming the tripod are secured bosses f project from the inner side of the pivotally, and to the upper end of which is turret, and a trough-shaped continuation of secured, preferably byscrewing on, as shown, said bosses projects from the ends thereon 0 40 a spider B, through the arms of which, there at their lower side, in which is seated the being preferably three of such arms, pass the spirit-level F, consisting of a slotted metallic leveling-screws b. tube with the level-glass seated therein, as C is the circle-plate, which is preferably ordinarily. This spirit-level is held in place saucer shape, being depressed in its center by screws f, passing downwardly through its 5 P and perforated in the bottom of said depresends into the respective trough-shaped prosion, a screw 0 passing through said perforajection, while other screws f pass upwardly tion and screwing into the spider B in such through said projections near their inner a manner that the circle-plate may have ends and bear their ends against the lower movement on said screw as on a universal side of the said level, whereby either of said too joint, a spring a being interposed between ends maybe elevated to throw the spirit-level the bottom of said depression and the head into practically'absolute parallelism with the edge of the turret and the sighting-tube. The ends of the metallic tube of the spirit-level Fcontact with the faces of the bosses f, which bosses for sake of neat appearance should be about the same diameter as said tube. One end of the tube E is provided with the usual crossed hairs and the other end with a novel form of adjustable sighting-hole, which I will now proceed to describe.

As seen in Figs. 1 and 2, a suitable slipsocket gis provided,having an eccentric plate g. The slip-socket fits the outside of the tube E and holds the plate 9 at substantially a right angle to the axis thereof. A disk G is rotatably mounted on the face of said plate and is provided with a spiral series of holes 9 the holes of said series being at an increasing distance from the center of said disk G in a regular ratio, the terminal holes of said series being capable, respectively, of locating concentrically of the sighting-tube and at an extra elevation, so that with the disk G in normal position a central sight-hole is provided which in connection with the crossed hairs will project the horizontal plane, and as the said disk is rotated in place the said sight-hole will be gradually elevated with relation to said crossed hairs and a correlastructed as shown in Fig. 3that is, of a single piece of wire bent in the form of a coil with a right-angle return-bend, the back end g of which rests upon the outside of the slipsocket g, while the front end (the pawl proper) rests in the notch in the plate 9 and the contignous notch in the edge of the disk, the coil lying across the top of the said return-bend and additively increasing the downward pressure of the pawl proper into the said notches.

This adjustable sighting device may be turned into any position on the sighting-tube one end of said tube and so give a predetermined degree of deflection of the plane projected in any direction.

Havingthus described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In a levelinginstrumeut, asighting-tube and means for leveling same, and a sight-adjusting device consisting of a plate secured to one end of said tube, and a disk rotatably mounted on said plate having a series of holes therein at different radial distances adapted to register with said tube.

2. In a levelinginstrument, a sighting-tube and means for leveling same, and a sight-adjusting device consisting of a plate secured to one end of said tube, and a disk rotatably mounted thereon having a series of holes therein at different radial distances and a latch adapted to engage said disk for locking thesame.

3. In a leveling instrument, a sighting-tube and means for leveling same, and a sight-adjusting device consisting ofa plate secured to and a disk rotatably mounted on said plate and having a series of holes therein, at difierent radial distances, and means for locking same consisting of a spiral-spring coil having its end bent laterally into contact with and within said coil and a return-bend projecting on the other side and adapted to engage the disk.

4. In a leveling instrument, a circle-plate having a circular seat in its upper side, means for leveling said circle-plate, an annular turret provided with parallel edges and fitting said seat and having, at diametrically opposite points, apertures, one of which is elongated vertically, in the apertures in said turret and adjusting screws located in one of 'said apertures for the purpose of adjusting said tube.

In testimony whereof I hereunto affix my signature in presence of two witnesses.

ERNST A. BOSTROM.

Witnesses:

EDWD. P. WOOD, A. P. Wool).

and a sighting-tube located 

